Improvement in surveyorsj targets



S. HASLETT. Surveyors Target.

C Y u r Y wav vl qm. S hllwl "www UNITED. i STATES PATENT OFFICE.

SULLIVAN HASLETT, OF BROOKLYN, NEV YORK.

lMPROVEMENT IN SURVEYORS TARGETS..

Specification forming part of Letters Patent No. 221,916, dated November25, 1879; application filed April 2l, 1379.

To all whom 'it may concern:

Be it known that I, SULLIvANHAsLETT, of Brooklyn, in the county of Kingsand State of New York, have invented a new and useful Improvement inSurveyors Targets; and I do hereby declare that the following is a full,clear, and exact description of the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,making part of this specification.

This invention is .in the nature of an improvement in surveyors7targets; and the invention consists in a surveyors target constructedwith a micrometer adjusting-screw and clamping-screws, whereby thetarget may be accurately adjusted .to the divisions on the ,surveyorsstaff, and whereby the sliding portion of the staif itself may beadjusted, in the manner hereinafter more particularly described.

In the accompanying," sheet of drawings, Figure lis a front view oftarget and statt; Fig. 2, a side view of `my invention; Fig. 3, areverse side view of same; Fig. 4, a section through line w m, Fig. l;Fig. 5, a cross-sec tion of adjusting devices, showing micrometer-screwand springs; Fig. 6, a front view of adjusting devices, with sleevespartly in section, in line y y, Fig. 5; and Fig. 7, front view of stalf,showing. interior slidev and interior markings.

Similar letters =of reference indicate parts in the several figures.

In surveying and leveling, the well-known target is ordinarily adjustedto the divisions on the surveyors staff by hand, and the frequentinaccurate adjustment in this Way has led to errors, and also to loss oftime in making the adjustment. The same remark applies also to theadjustment of the sliding portion of the surveyors staff-that is, theaccurate adjustment of the slide to the divisions of the scale formedbetween the sliding surfaces of the staff.

To obviate these difficulties I construct my target A, which may be ofany desired size or shape on its face, with a bracket or sleeve, B. Thissleeve is firmly secured lto the back of the target, and is preferablyrectangular in shape. Within the sleeve B is accurately tted a secondsleeve, C, which is not' attached like to the target, but which isconstructed to permit the surveyor-s stati D to pass through it, withsuflicient space between the surface ot' the staff D and the innersurface of the sleeve O to allow the interposition of lia-t springs a I)c d, which are secured within the sleeve C. The sleeve B on one side hasformed in it a slot, c, which slot is parallel with the length of thestat't'D, and the sleeve O likewise has a small slot, j, formed in oneof its sides, which last-mentioned slot is also parallel with the staffD.

To the sleeve .O is fixed a stud, j', which passes through the slot e inthe sleeve B. This stud has screw-threads formed in it', which receivethe threads of a screw, g, with a milled head, h, formed on it, andthrough the sleeve B passes a screw, fi, which screw enters into theslotj in the sleeve C.

To the rear .side of the sleeve B is fixed or formed a projection, 7c,and within this projection is iitted a sliding nut, Z. This nut has madein it screw-threads into which passes a screw, E, working in bearin gs mand a, formed on the rear side of the sleeve O, the screw E beingprovided with a milled head, o.

The staff D vemployed is the ordinary surveyors staff, with thedivisions r on its face, and made in two parts, s and t, which slidetogether, and also with divisions o on the slide w.

My target, constructed substantially as above described, is operated asfollows: It is moved by hand until the dividingliine y on its face isnearly coincident with the marking ou thelscale r on the face of thestaff, or as nearly as may be to the height indicated by the surveyor,in which position it is held by turning the clamping-screw g, whichforces the spring d against the side of the staff, tightly clamping thetarget in position. Then, when a more accurate adjustment requires thi-etarget to be moved carefully up or down from its clamped position, asbefore stated, the micrometer-screw E is turned to the right or left,thereby raising or lowering the target with accuracy to a given positionon the staff. This raising and lowering of the target is accomplished bythe action of the micrometer-screw working through the nut l, which isiixed to the sleeve C, so that as this sleeve is clamped n to the staffby the binding-screw g the sleeve B slides over the surface of thesleeve G, carrying` the target A, which is iiXed to it, as beforestated. This action of the micrometer, screw E not only adjusts thetarget on the staff with great nicety, but it also holds the targetiiXed in whichever position it may be adjusted by the action of thescrew E.

The purpose of the slot c in the sleeve B is to permit the sliding`movement of the sleeve without interruption from the binding-screw g.

To adjust the sliding parts ot' the staff to the scale v on the slide w,a plate, a2, with a screw-hole formed therein, is countersunk andfastened to the side of the face-section or sliding part s, of thestatt', and the sleeve B is moved up to that plate, or the stail isotherwise adjusted so that the screw t' may enter into the screw-holeformed in the plate a2, thereby firmly clamping the sleeve B to the face0r sliding part s ofthe statt', and when so fixed, by releasing theclamping-screw g and turning the micrometer-screw E, the two sections 0fthe staffs and t will be made to slide on each other up or down, as maybe desired, till an apprcximately-accurate adjustment of the height ofthe statt' is obtained. Then by tightening the screw g the accurateadjustment is effected by the action of the micrometerscrew E, whichcauses the sleeve B to slide up and down on the sleeve C as the screw isturned to the right and left; and since the sleeve B is practicallyscrewed fast to the front sliding4 portion, s, of the staff', as beforedescribed, this front portion ot' the staff is carried by the sleeve Bby its movement, as before stated.

Vhen adjusting thc target so that this adjustment of the length of thesta-ft' by the micrometer-screw is desired, it is necessary to slackenup the clamping-screw g, so as to permit the two sections of the staii'to freely slide upon each other. The slot j in the sleeve C permits thesleeve C to move up and down unobstructed by the screw The purpose ofthesprings 11,1), and c is to cause the target to slide steadily' withoutwabbling and with ease on the stai D. The spring` d also assists in thatparticular, and besides acts as a clamp in connection with the screw g,as hereinbe-fore described.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, .is-

1. A surveyors target, A, in combination` with sleeves B and C,micrometer-screw E, and staff D, substantially as and for the purposedescribed.

2. In a surveyors target, the combination of a micrometer-screw, E, aclamping-spring, a, and clamping-screw t', substantially as and for thepurpose described.

3. In a surveyors target, the combination of a micrometer-screw, E, aclamping or holding screw, g, and sliding sections s and t ot a-`surveyors stati', D, substantially as and for the purpose described.

4. In a surveyors target, the combination of the staff D, the sleeve B,sleeve C, micrometer-screw E, clamping-screws g and t', and

springs a b c d, substantially as and for the purpose shown anddescribed.

SULLIVAN HASLETT. Witnesses:

H. L. WATTENBERG, G. M. PLYMPTON.

